Immobilization of a rhodium catalyst using a diphosphine-functionalized ionic liquid in RTIL for the efficient and recyclable biphasic hydroformylation of 1-octene

2016 ◽  
Vol 190 ◽  
pp. 219-230 ◽  
Author(s):  
Yong-Qi Li ◽  
Huan Liu ◽  
Peng Wang ◽  
Da Yang ◽  
Xiao-Li Zhao ◽  
...  

A highly efficient and stable Rh–P catalytic system in the RTIL of [PEmim]BF4 was developed for the biphasic hydroformylation of 1-octene by using the diphosphine-functionalized ionic liquid (FIL) of 2. While 2-Rh(acac)(CO)2 was immobilized in [PEmim]BF4 (solvent), a typical biphasic catalysis was fulfilled with advantages of facile separation and recycling ability – 9 runs without any loss of activity. It was found that not only the acquired π-acceptor character of 2, but also the synergetic role of the piperidyl group in [PEmim]BF4 as an N-containing donor, cooperatively contributed to the efficient hydroformylation due to the facilitated formation and stability of the Rh-H active species (ν 2045 cm−1). This was supported by the in situ high-pressure FT-IR spectral analysis.

Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 824
Author(s):  
Przemysław J. Jodłowski ◽  
Izabela Czekaj ◽  
Patrycja Stachurska ◽  
Łukasz Kuterasiński ◽  
Lucjan Chmielarz ◽  
...  

The objective of our study was to prepare Y-, USY- and ZSM-5-based catalysts by hydrothermal synthesis, followed by copper active-phase deposition by either conventional ion-exchange or ultrasonic irradiation. The resulting materials were characterized by XRD, BET, SEM, TEM, Raman, UV-Vis, monitoring ammonia and nitrogen oxide sorption by FT-IR and Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS). XRD data confirmed the purity and structure of the Y/USY or ZSM-5 zeolites. The nitrogen and ammonia sorption results indicated that the materials were highly porous and acidic. The metallic active phase was found in the form of cations in ion-exchanged zeolites and in the form of nanoparticle metal oxides in sonochemically prepared catalysts. The latter showed full activity and high stability in the SCR deNOx reaction. The faujasite-based catalysts were fully active at 200–400 °C, whereas the ZSM-5-based catalysts reached 100% activity at 400–500 °C. Our in situ DRIFTS experiments revealed that Cu–O(NO) and Cu–NH3 were intermediates, also indicating the role of Brønsted sites in the formation of NH4NO3. Furthermore, the results from our experimental in situ spectroscopic studies were compared with DFT models. Overall, our findings suggest two possible mechanisms for the deNOx reaction, depending on the method of catalyst preparation (i.e., conventional ion-exchange vs. ultrasonic irradiation).


2013 ◽  
Vol 117 (24) ◽  
pp. 12661-12678 ◽  
Author(s):  
Kaustava Bhattacharyya ◽  
Alon Danon ◽  
Baiju K.Vijayan ◽  
Kimberly A. Gray ◽  
Peter C. Stair ◽  
...  

2020 ◽  
Vol 13 (05) ◽  
pp. 2051031
Author(s):  
Abulikemu Abulizi ◽  
Hujiabudula Maimaitizi ◽  
Dilinuer Talifu ◽  
Yalkunjan Tursun

A photocatalyst of high-performance hierarchical nitrogen-doped MoS2 (N-MoS2) microsphere was fabricated by an in situ hydrothermal method in the presence of cetyltrimethylammonium bromide (CTAB). The as-prepared N-MoS2 microsphere was self-assembled by extremely thin interleaving petals, where CTAB acts as a nucleation site for the formation of the interleaving petals due to the strong interaction between CTA+ and [Formula: see text]. N-MoS2 showed higher N2 fixation ability (101.2 [Formula: see text] mol/g(cat)h) than the non-doped MoS2 under the visible light irradiation, and the improved photocatalytic activity could be ascribed to that the doped N narrows the band gap, and the surface reflecting and scattering effect caused by the hierarchical structure enhance the light adsorption. The trapping experiment of active species was also investigated to evaluate the role of photogenerated electrons in the photocatalytic reaction process. Meanwhile, the possible mechanism for the formation and excellent photocatalytic performance of N-MoS2 microsphere were also presented.


Author(s):  
Anastasia Filtschew ◽  
Pablo Beato ◽  
Søren Birk Rasmussen ◽  
Christian Hess

The role of platinum on the room temperature NOx storage mechanism and the NOx desorption behavior of ceria was investigated by combining online FT-IR gas-phase analysis with in situ Raman...


2021 ◽  
Author(s):  
Guiling Shi ◽  
Ran Zhai ◽  
Haoran Li ◽  
Congmin Wang

A dual functionalized ionic liquid catalytic system was developed for the reaction between CO2 and propargylic alcohols, and exhibited excellent performance and good reusability, even under a low concentration of CO2 in a gram-scale reaction.


2019 ◽  
Vol 17 (1) ◽  
pp. 73-83
Author(s):  
Praveenkumar Ramprakash Upadhyay ◽  
Prashant Gautam ◽  
Vivek Srivastava

new Pt metal based nano-catalytic system was developed using organic-inorganic magnetic framework followed by the user-friendly protocol in good yield. XRD, FTIR, TEM, BET, ICP-OES and solid-state NMR techniques were used to characterize our developed catalytic system. The wellcharacterized ionic liquid bridged-silica supported magnetic Pt nanoparticles were utilized for the selective hydrogenation of carbon dioxide under high-pressure reaction condition (with and without ionic liquid medium). Most promising results were obtained while using the catalytic system (Pt-MagNP@ILSiO2) in 1,3-di (N, N-dimethylaminoethyl)-2-methylimidazolium nonafluorobutanesulfonate ([DAMI] [CF3CF2CF2CF2SO3]) task-specific ionic liquid medium. This TSIL not only provided a high degree of CO2 absorption during the reaction but also enhances the selectivity and the recyclability of the catalytic system up to 8 runs. No sign of Pt metal leaching was recorded during the recyclability test which confirmed the stability of this catalytic system under high-pressure reaction condition.


2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
F. Basile ◽  
I. Bersani ◽  
P. Del Gallo ◽  
S. Fiorilli ◽  
G. Fornasari ◽  
...  

Supported Rh nanoparticles obtained by reduction in hydrogen of severely calcined Rh/Mg/Al hydrotalcite-type (HT) phases have been characterized by FT-IR spectroscopy of adsorbed CO [both at room temperature (r.t.) and nominal liquid nitrogen temperature] and Transmission Electron Microscopy (TEM). The effect of reducing temperature has been investigated, showing that Rh crystal size increases from 1.4 nm to 1.8 nm when the reduction temperature increases from 750°C to 950°C. The crystal growth favours the formation of bridged CO species and linear monocarbonyl species with respect to gem-dicarbonyl species; when CO adsorbs at r.t., CO disproportionation occurs on Rh and it accompanies the formation of RhI(CO)2. The role of interlayer anions in the HT precursors to affect the properties of the final materials has been also investigated considering samples prepared from silicate-instead of carbonate-containing precursors. In this case, formation of RhI(CO)2 and CO disproportionation do not occur, and this evidence is discussed in terms of support effect.


RSC Advances ◽  
2013 ◽  
Vol 3 (23) ◽  
pp. 8796 ◽  
Author(s):  
Chang Wang ◽  
Xiumei Liu ◽  
Miao Yang ◽  
Huiyuan Ma ◽  
Peifang Yan ◽  
...  

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